The Cummins engine continues with both Standard and High Output versions.
Starting in January 2003, the High-Output engine will be available with
automatic transmission. Comparative engine ratings are as follows:

49-State High Output Engine

Rating Factor

2002 Rating

2003 Rating

Horsepower

245 bhp (183 kW) @ 2700 rpm

305 bhp (227 kW) @ 2900 rpm

Torque

505 lb.-ft. (685 N*m) @ 1,600 rpm

555 lb.-ft. (752 N*m) @ 1400rpm

49-State Standard Output Engine

Rating Factor

2002 Rating

2003 Rating

Horsepower

235 bhp (175 kW) @ 2700
rpm

250 bhp (186 kW) @ 2900 rpm

Torque

460 lb.-ft. (624 N*m) @
1600 rpm

460 lb.-ft. (624 N*m) @ 1400 rpm

California Standard Output Engine

Rating Factor

2002 Rating

2003 Rating

Horsepower

235 bhp (175 kW) @ 2700
rpm

235 bhp (175 kW) @ 2700 rpm

Torque

460 lb.-ft. (624 Nˇm) @
1600 rpm

460 lb.-ft. (624 Nom) @ 1400 rpm

TRAILER TOWING

The high-output Cummins Turbo Diesel engine with manual transmission gives Ram
the highest GCWRs (Gross Combined Weight Rating) in the heavy-duty pickup
segment. It is rated at up to 23000 pounds GCWR. Rear axle ratios are now 3.73
or 4.10

GCWRs have also increased for most other models as well. Rear springs have been
selected to keep the tail gate height below 57.5 inches (1460 mm) to accommodate
more fifth-wheel trailers than the 2002 models did.

Cummins Turbo Diesel Engine

Extensive redesign of the Cummins Turbo Diesel engine included major emphasis on
minimizing traditional diesel engine noise. Noise level of all versions of the
engine have been reduced substantially and now approach those of gasoline
engines. The most notable areas of noise reduction are at idle, especially when
the engine is cold, and under light-load acceleration and cruising conditions.

The major contributing factor to combustion noise reduction is new high-pressure
common rail electronic fuel injection. This system uses pilot injection, the
injection of a small amount of fuel that starts combustion, before the main,
power-producing, fuel charge is injected. This has the effect of smoothing out
combustion pressure in the cylinder, which is the primary source of low-speed
noise in diesel engines. In addition to the use of pilot injection to smooth
combustion pressure, the fuel injection calibration -

For California, Ram Pickups powered by the Cummins Turbo Diesel engine include
an underfloor oxidation catalytic converter as in 2002. For the other 49 states,
the exhaust need no after-treatment to meet emission standards

CUMMINS TURBO DIESEL ENGINEGeneral Information

Extensive improvements to the
proven Cummins diesel engine for the 2003 model year provide

More power and torque

Noticeably quieter operation

Reduced maintenance

Reduced exhaust emissions

The Cummins engine continues with both Standard and High Output versions.
Starting in January 2003, the High-Output engine will be available with
automatic transmission.

Figure 2: Cummins Turbo Diesel Engine

Power and Performance

The high-output engine, which is not available in California, produces nearly 25
percent more peak power and 10 percent more torque than the 2002 version. The
Standard-Output engine available in 49 states produces over 6 percent more power
than in 2002. A Standard Output California-version is also available.

All versions of the Cummins engines feature a 400 rpm-wider maximum torque range
than in 2002 - 200 rpm below and 200 rpm above the previous range. The maximum
torque occurs 400 rpm lower than the GM Duramax, and 200 rpm lower than the Ford
Power Stroke. These engines also produce 20 percent more torque at 1000 rpm, and
10 percent higher clutch engagement torque than their predecessors. These
performance improvements result in:

The engine responds faster to changes in accelerator pedal position as a result
of Cummins' proprietary engine control system and a state of the art common-rail
electronic fuel injection.

A gear driven injection pump delivers a fuel to the rail that is electronically
controlled to optimize fuel pressure at the individual injectors. The system
provides injection pressures up to 23,200 psi (1600 Bar) that are less dependent
on engine speed than the traditional pump-line injection system. The result is
cleaner combustion and higher low speed torque with better vehicle response and
acceleration.

Cummins' controls and the electronic fuel injection ensures that the engine
combines optimum fuel economy and performance with emission control capabilities
to meet increasingly stringent emissions regulations. In addition, the
common-rail architecture and electronic controls are capable of providing new
features, such as multiple injection pulses, and independent control of
injection pressures. This provides both noticeably quieter operation and
improved cold start capability..

Both engines share a higher compression ratio that contributes to the increased
power and torque. For the standard-output engine, the increase to 17.2:1 is
almost one full ratio.

Reduced wait-to-start" times up to 15 seconds less at temperatures below 20 °F
(7°C)

Significantly reduced cold cranking times

Reduced manifold heater power consumption

For cold starting, the engine continues to use an electronically controlled
intake air heater grid, mounted at the inlet to the intake manifold, that is
inherently more reliable than the glow plugs used in competitive engines.

Quality and Reliability Features

The Cummins Turbo Diesel engine is renowned for its durability, being used in
commercial medium-duty and heavy-duty applications worldwide. The simple
inline-six cylinder design has up to 40 percent fewer parts than competitive V-8
diesel engines. And the Cummins engine has an average life to overhaul of
350,000 miles, compared to 250,000 for competitive engines. Because of its
longevity, the Cummins engine is rated as a "medium-heavy duty" engine, compared
to the "light-heavy duty" designation for GM Duramax and Ford Power Stroke
diesels.

All versions of the engine use valve seat inserts for added durability. And the
High-Output engine employs gallery cooled pistons -internal oil passages in the
pistons that lower piston operating temperatures for longer life at the higher
power levels this engine produces.

The new self-priming fuel system enables fast and easy re-starts after routine
fuel filter changes, and avoids manual priming and costly road service calls if
the vehicle runs out of fuel.

Exhaust Emission Control Features

The redesigned combustion system reduces NOx and hydrocarbon emissions by 25
percent on California. For the 49-State engines, power and performance are
enhanced while still meeting current emissions regulations. The new controls and
fuel system technology also enable the engines to meet increasingly stringent
future emissions standards.

Serviceability Features

The redesigned engine provides the following key serviceability improvements:

Longer oil change intervals

Better oil filter accessibility

Self-priming fuel filter

In normal service the oil change interval increases from 7,500 to 15,000 miles;
the trailer towing (severe service) oil change interval also increases - from
3,750 to 7,500 miles. Soot reduction resulting from cleaner combustion is the
primary enabler for the extended oil change intervals. Oil change capacity
remains at 12 quarts including oil in the filter.

Enhanced oil filter accessibility results from relocating air conditioning
refrigerant lines and coolant lines. The addition of flutes to the filter
housing allows use of a cap-style filter wrench for easier removal and
installation.

The new fuel system enables fast and easy re-starts after routine fuel filter
changes, and avoids manual priming and costly road service calls if the vehicle
runs out of fuel.

All accessories are driven by a single serpentine belt with automatic tensioner,
whereas the power steering pump was previously gear driven. Accessory drive
ratios have been optimized for improved performance over a wide range of
conditions.

Figure 4: Cummins Turbo Diesel Engine Accessory Drive System

AIR INDUCTION SYSTEM

2500 and 3500 Ram Pickups with gasoline engines use the same air cleaner and
filter element as the 1500s. With these engines, the air cleaner inlet extends
through a shield that separates the outer fender area from the engine
compartment to provide cooler air to the engine. With diesel engines, a larger
air cleaner assembly and filter are used because of the higher air consumption
of these engines. As in 2002, the air cleaner housing includes a Filter Minder
device to help determine when the filter needs to be replaced. Both air cleaner
housings mount on the frame rail in the right front corner of the engine
compartment.

TRANSMISSIONS
48RE FOUR-SPEED AUTOMATIC TRANSMISSION

The 48RE automatic transmission will be optional on 2500 and 3500 series with
both

Cummins diesel engines and with the 8.0-liter gasoline engine beginning in
January 2003. It is a beefed up version of the 47RE automatic transmission,
which it replaces. Extensive internal modifications give it the torque capacity
and durability required to work with the redesigned High Output Cummins diesel
engine. This is the first automatic transmission available with the High Output
engine. The internal modifications also give the transmission a design life of
150,000 customer-equivalent miles. Contributing to the durability and long life
is electronic torque management - limiting engine torque build up when
initiating acceleration from a stop. The 48RE transmission retains all the
features of the 47RE, including the electronically controlled governor, and the
same gear ratios.

For states that require vehicles to meet the California Emission Standards, the
Cummins Turbo Diesel exhaust system includes a single underfloor catalytic
converter. For those states which do not require vehicle to meet this standard
the converter is replaced by an exhaust resonator.

ENGINE COOLING SYSTEMS

Full-width radiators are standard with Cummins Turbo Diesel and 8.0-liter
MagnumŽ V-10 gasoline engines due to higher cooling demands. In these cases, the
air-conditioning condenser, where used, mounts ahead of the radiator in a
conventional manner. All models with the new 5.7-liter HEMIŽ MagnumŽ V-8 engine
have the radiator and air conditioning condenser mounted side-by-side, as on all
2002 models. Benefits of this arrangement remain the same: reduced fan power
loss and quieter fan operation.

An electronically controlled viscous fan drive is included with the Cummins
Turbo Diesel engine. It reduces noise and fuel consumption, compared to the
prior thermostatically controlled viscous drive system, when added cooling air
provided by the fan is not needed. This form of control also allows the use of a
larger fan than in the past to maximize cooling under extreme conditions. The
fan can consume up to 25 horsepower at high rpms. The PCM operates a solenoid
valve on the fan drive that controls flow of the viscous material, determining
when fan engages and disengages and also how fast it turns. Coolant temperature
and air conditioning refrigerant pressure are the primary inputs that determine
fan operation. Previously, only underhood air temperature was used to determine
whether the fan ran or not. Electronic control also enables electronic
diagnostic capabilities for fan drive operation. Viscous coupling of the fan to
the engine continues to limit fan speed at high engine speed.

NVH--Cummins Turbo Diesel Engine

The Cummins Turbo Diesel engine for 2003 is noticeably quieter than in prior
model years. The noise levels of all versions of the engine have been reduced
and approach those of gasoline engines. Noise is lower across the entire
operating speed range, especially at idle and during cruise conditions.

The following features contribute to noise reduction:

Multiple fuel injections: The high pressure common rail system enables the
use of multiple injections which reduce the rate of pressure rise in the
cylinders - a primary sources of noise in diesel engines.

Block stiffening: The addition of a bedplate to increase crankshaft support
reduces structure-related noise.

Redesigned turbocharger components:
Better balancing of the rotating components and improved dimensional control
reduces mechanical noise under high load operation. A new intake silencer
eliminates airflow noise from the turbocharger.